UNION CITY — With a yearlong moratorium to expire in July, city leaders are set to slam the door on medical marijuana dispensaries for the foreseeable future.

Today, the City Council will consider a law that would require any permit, authorization or license issued by the city to “be consistent with both state and federal law.”

Because federal drug laws prohibit medical marijuana, the city ordinance effectively would outlaw dispensaries — the most common way licensed marijuana users obtain the drug.

“It’s not an outright ban, but in the short term it would make it difficult, if not impossible, to operate a dispensary,” Deputy City Manager Tony Acosta said.

He said the city does not want dispensaries while cases on medical marijuana issues are pending in state and federal courts.

The proposed ordinance is a new legal tactic to outlaw dispensaries, said Kris Hermes, legal campaign director for Americans for Safe Access, which has lawsuits pending against several California cities that prohibit dispensaries.

“We would see this as a de facto ban and strongly oppose such action by the city,” he said.

Robert Raich, an attorney who represents dispensaries, said the ordinance was “vaguely worded” and effectively would make city permit clerks the arbiters of state and federal law.

“Union City is practically buying a lawsuit down the road,” he said.

Since state voters passed the Compassionate Use Act of 1996 legalizing medical marijuana, dispensaries in the East Bay have spread from Berkeley south to Hayward but have not been permitted in Union City.

In March 2005, the council, after learning that a dispensary had applied for a city permit, passed the first of three moratoriums temporarily outlawing it. Fremont also has a moratorium against dispensaries.

The moratoriums, according to Hermes, force many licensed medical marijuana users in the two cities to travel north to obtain the drug legally.

About 30 percent of the customers of the Hayward Patients Resource Center are from Union City and Fremont, said Tom Lemos, the dispensary’s owner.